Nonfluorescent, green-yellow cationic dye

ABSTRACT

A nonfluorescent green-yellow cationic dye having the formula:   WHEREIN X is one of a variety of anions.

United States Patent [191 Hunter NONFLUORESCENT, GREEN-YELLOW CATIONIC DYE [75] Inventor: Frank Ray Hunter, Newark, Del.

[73] Assignee: E. I. du Pont de Nemours and Company, Wilmington, Del.

[22] Filed: May 14, 1973 21 Appl. No.: 359,682

Related U.S. Application Data [63] Continuation-impart of Ser. No. 792,781, Jan. 21,

1969, abandoned.

[ 1 Dec. 10, 1974 2,155,447 4/1939 Roh et al. 260/2408 2,263,749 1 H1941 White et al. 260/2408 2,906,588 9/1959 Brunkhorst, et al. 260/2408 X Primary Examiner.lohn D. Randolph Attorney, Agent, or Firm-James A. Costello [57] ABSTRACT A nonfluorescent green-yellow cationic dye having the formula:

wherein X is one of a variety of anions.

2 Claims, No Drawings NONFLUORESCENT, GREEN-YELLOW CATIONIC DYE CROSS-REFERENCE TO RELATED APPLICATION This is a continuation-in-part of copending Application Ser. No. 792,781, filed on Jan. 21, 1969, and now abandoned.

BACKGROUND OF THE INVENTION CII;

yCH-Ng A tinctorially strong position isomer of the dye disclosed herein is taught in U.S. Pat. No. 2,155,447. Its formula is //CH--N 01- The properties of these prior art dyes compared to those of the dye of this invention will be discussed'hereafter under the heading Properties of the Novel Dye.

SUMMARY OF THE INVENTION The present invention comprises a nonfluorescent green-yellow cationic dye of the formula where X is an anion such as chloride, bromide, iodide, sulfate, chlorate, phosphate, fluoroborate, picrate, acetate and arylsulfonate. It is preferred'that X" be the chloride anion.

The process for preparing the novel dye comprises condensing l,3,3-trimethyl-2-methylene indolineomega-aldehyde with l ,2,3 ,4-tetrahydro-6- methoxyquinoline in equimolar amounts in a lower alkanol. A catalyst such as mineral acid or phosphorus oxychloride is then slowly added and the resultant precipitate is heated to redissolve. The desired dye is then reprecipitated by salting, cooled and dried.

DETAILS OF THE INVENTION When a mineral acid catalyst is utilized in the preparation of the dye of this invention, it is added slowly to a solution of equimolar quantities of 1,3,3-trimethyl- 1,2-methylene indoline-omega-aldehyde (Fischers Aldehyde) and l,2,3,4-tetrahydro-6-methoxyquinoline in a lower alkanol, preferably methanol, said solution containing up to about 45 percent by weight of solids. While the amount of mineral acid employed is not critical the ratio should be at least about 1 mole of mineral acid per mole of Fischers Aldehyde and an excess of more than 2 mole of mineral acid per mole of Fischers Aldehyde serves no beneficial purpose. While the par-' ticular mineral acid employed is not critical, hydro chloric acid is preferred. Sufficient solvent is used to maintain solubility, stirrability and ease of reaction.

The reaction mixture is then agitated for 1-2 hours at a temperature of from 50C. to the boiling point of the solvent used. Water is then added (about 60-70 percent by weight of the reaction mass) and this aqueous alcoholic mixture is heated to a temperature of from 60 C. to the boiling point of said aqueous alcoholic mixture. The dye is then precipitated by salting, cooled to O-l5C., and isolated by filtration.

Should the catalayst employed be phosphorous oxy-' chloride,it is added slowly to a 15-35 percent solution of equimolar amounts of Fischers Aldehyde and 1,2,3- ,4-tetrahydro-6-methoxyquinoline in an organic solvent containing about 5-15 percent of a lower alkanol, preferably methanol. While the amount-of phosphorus oxychloride employed is not critical the ratio should be at least about 0.33 mole of phosphorus oxychloride per mole of Fischers Aldehyde and an excess of more than 0.66 mole of phosphorus oxychloride per mole of Fischers Aldehyde serves no beneficial purpose. Stirring is maintained throughout this mixing step and the temperature is kept below 35C., since higher temperatures produce a red impurity which decreases the yield of desired product. For this reason the addition of the phosphorus oxychloride must be slow. The reaction mixture is then heated to 75.- C. to redissolve the precipitated product of said mixture. The desired dye is then reprecipitated by salting with an additive such as sodium chloride, cooled and isolated by filtration. This preparation can be effected in various organic solvents including benzene, monochlorobenzene, nitrobenzene, and the like, however xylene is preferred. Sufficient solvent is used to maintain solubility, stirrability and ease of reaction.

The anion may be varied depending on the physical form of the dye desired, some examples of possible anions being bromide, iodide, sulfate, chlorate, phosphate, fluoroborate, picrate, acetate and p-toluenesulfonate, with chloride being the preferred anion.

PROPERTIES OF THE NOVEL DYE In comparison to the novel dye herein, the analog is tinctorially weaker to a significant degree and displays poorer exhaust and buildup while the isomer displays poorer lightfastness and is fluorescent. The importance of the property of lightfastness is understood clearly by those skilled in the art who also appreciate the conditions under which differences in lightfastness are most readily demonstrable.

The cationic dye of this invention is valuable for dyeing acid-modified acrylic and polyester fibers and has outstanding fastness to light on these fibers. lt exhibits excellent reserve on wool, cotton and unmodified polyamide and polyester, rendering the dye useful for the coloration of various blend fabrics containing one or more of these fibers and an acid-modified fiber, and is also stable to heat. This heat stability is particularly important if the dye is to be used on carpeting, which is subjected to dry heat after dyeing to cure a latex backing. Further, the instant dye is resistant to hydrolysis and shows no shade change over the pH range 2-8.

The following Examples are intended to illustrate the invention and are not meant to limit theinvention. Unless otherwise indicated, all quantities are by weight.

EXAMPLE 1 Preparation of the Dye Utilizing a Mineral Acid Catalyst A solution of 10 parts of l,2,3,4-tetrahydro-6 methoxyquinoline and 158 parts of Fischers Aldehyde in 32 parts of methanol were warmed to 35C. with stirring. 6.9 Parts of concentrated hydrochloric acid were added over 20 minutes at 3540C. and the reaction mixture stirred for 1%. hours at 5055C. 40 Parts of water were then added and the reaction mixture heated to 60C. l5 Parts of sodium chloride were added and the reaction mass cooled to ll C., precipitating the dye. The product was filtered, washed with 160 parts of ice water and dried at 65C.

The product thus obtained has the formula:

Preparation of the Dye Utilizing Phosphorus Oxychloride Catalyst A solution of 555 parts of l,2,3,4-tetrahydro-6- methoxyquinoline in 1450 parts of xylene and 220 parts of methanol is put into a vessel equipped with an external means of cooling. A nitrogen blanket is maintained in the vessel, to which is added 685 parts of dry Fischer's Aldehyde. The mass is cooled to l0l5C. and 190 parts of phosphorus oxychloride are added over 55-60 minutes. with agitation, the temperature being held below 35C. The dye precipitates from solution on forming. The reaction mixture is stirred for 3 hours after addition of phosphorus oxychloride is complete at 35C. or below.

3600 Parts of water are then added and the temperature raised to 80C. to dissolve the dye. 230 Parts of salt EXAMPLE 3 (Utility) Dyeing of Acid-Modified Acrylic Fiber Preparation of Fiber A S-gram skein of acid-modified acrylic fiber was scoured for 15 minutes at 160F. in a 200 ml. aqueous bath containing the following:

tetrasodium pyrophosphate 0.05 gram the condensation product of 20 moles of ethylene oxide with one mole of C alcohol 003 gram.

The skein was rinsed thoroughly with water. Dyeing Procedure A ZOO-ml. aqueous dyebath was prepared which contained the following:

dye 0.0075 gram the condensation product of 20 moles of ethylene oxide with l mole of C alcohol 0.015 gram sodium sulfate (anhydrous) 0.500 gram C alkyl trimethylammonium bromide 0.30 gram glacial acetic acid 0.050 gram The S-gram skein was added and the temperature raised to boiling for 1-2 hours. The skein was rinsed in water, scoured for 15 minutes at 160F. with 200 ml. of water containing 0.05 gram of the condensation product of 20 moles of ethylene oxide with 1 mole of C alcohol, rinsed and dried.

EXAMPLE 4 (Utility) Dyeing of Acid-Modified Nylon Preparation of Fiber A 5-grarn skein of acid-modified nylon was scoured for l5 minutes at 160F. in a 200 ml. aqueous bath containing sodium perborate 020 grain a sull'obetaine 0.006 gram (fHzCHg 0 II isalkyl 307 R-I?T-CH;CH;CH;SO where R C nalkyl (3092 CnmOnO-unsaturated to 100% CHqCI-h O H The skein was rinsed thoroughly in water. Dyeing Procedure The S-gram skein was added to a ZOO-ml. aqueous dyebath containing:

The aforementioned sulfobetaine 0.050 gram The tetrasodium salt of ethyl enediamine tetraacetic acid 0.0[3 gram Tetrasodiurn pyrophosphate 0.050 gram The dyebath pH was adjusted to 6 with monosodium phosphate and the temperature raised to F. for 10 minutes. The dye (0.0075 gram) was added and the dyebath held at 80F. for an additional minutes. The temperature was then raised at a rate of 2F. per minute to 208F. This temperature was maintained for 1 hour. The skein was rinsed in water and dried. 5

EXAMPLE 5 (Utility) (Comparison) The following reported data illustrated the unexpected lightfastness of the subject dye on acid-modified acrylic and nylon fibers in comparison with its art- 1 known position isomer.

7 m Subject Dye CH3 crnol cm 15 Subject Dye Position lsomer Nitrogen Analysis Found: 5.8% Found: 6.0%

(iodide salts) Calcd: 5.9% Calcd: 5.9%

Amax 420 420 Absorptivity 133 124 The two dyes were applied to acid-modified acrylic and nylon fibers at the 0.15 percent level (on the weight of the fiber) by the methods described in Examples 3 and 4 respectively and subjected to an Xenon Arc Fade-OMeter for 320 hours. Also noted below is the fluorescence of the isomer vs. the nonfluorescence of the novel dye taught herein, when viewed under ultraviolet light.

The following shade and strength results were assessed according to the Gray'Scale as found in the Association of American Textile and Color Chemists Technical Manual. The Gray Scale chart showing degree of alteration in shade and strength is as follows:

5 Negligible or No Change 4 Slight Change 3 Noticeably Changed 2 Considerably Changed 1 Much Changed.

Acid Acid Acrylic Nylon Fiber Fiber Fluorescence Subject 4 dull, Dye 4-3 weak 4-3 weak Nonfluorescent Position 3 dull, Fluorescent isomer 2 weak 1 weak Thus,jthese data clearly demonstrate the unexpected superiority in lightfastness of the dye of this invention over the dye of the position isomer. That is, the shade remained brighter (significantly less dull) and the strength greater for the acrylic fiber dyed with the dye of this invention than for the acrylic fiber dyed with the isomer. The difference in strength between the nylon fiber dyed with the dye taught herein and the isomeric dye of the art is even greater and more significant.

EXAMPLE 6 (Comparison) A comparison of fabric dyed with the unsubstituted analog vs. fabric dyed with the dye of this invention in addition to supporting the greater tinctorial strength of the dye herein vs. the analog, also supports the improved properties of dye buildupand exhaust for the novel dye herein vs. the art-disclosed analog.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. A nonfluorescent green-yellow cationic dye of the formula OCH where X is an anion selected from the group consisting of chloride, bromide, iodide, sulfate, chlorate, phosphate, fiuoroborate, picrate, acetate and arylsulfonate.

2. A dye according to claim 1 wherein X is a chloride anion. 

1. A NONFLUORESCENT GREEN-YELLOW CATIONIC DYE OF THE DORMULA
 2. A dye according to claim 1 wherein X is a chloride anion. 